Method of generating gas



June 27, 1939.

A. J, DIESCHER METHOD OF GENERATING GAS 2 Sheets-Sheet 1 Filed Dec. 30,1957 1 m h fi INVENTOR fl/f/ e J D/esc/rer ATTORNEY June 27, 1939. A. J.DIESCHER METHOD OF GENERATING GAS Filed Dec. 50, 1937 2 Sheets-Sheet 2INVENTOR fl/fia am/ 8:

ATTORNEY Patented June 27, 1939 PATENT OFFICE METHOD OF GENERATING GASAlfred J. Diescher, Winfield, Kans., assignor to B. E. Hepler, New York,N. Y.

Application December 30, 1937, Serial No. 182,633

2 Claims.

This invention relates to a method of generating a gas, and particularlyto the enrichment of air with vapors of a normally liquid hydrocarbonsuch as a volatile distillate, for example gasoline. Individualapparatuses of this character are particularly useful for supplying gasin rural and suburban districts where conven tional gas supplies are notavailable for cooking, heating and similar domestic purposes. Whilethere is a large potential market for such apparatus by reason ofreadily available supplies of a suitable liquid hydrocarbon, they havenot proven successful because of ineiliciency, danger of explosions anddifficulty of adjustment and operation. These difiiculties have beenbrought about primarily by variation in prevailing atmosphericconditions and in contact time of the air with the distillate due tovarying levels of the contacting liquid in the apparatus. These variablefactors control the B. t. u. value of the gas for a given hydrocarbonand constant air supply. Tests have shown that full saturation of airwith distillate vapors drops rapidly as the temperature at the point ofenrichment lowers. Therefore when the apparatus is set to supply a gashaving sufiicient vapors or B. t. u. content to keep the gas above thecombustion or explosion range, drop in temperature results in loweringthe B. t. u. value into the explosion range and flash-backs are likelyto occur. Likewise, should the temperature rise at the point ofenrichment, condensation occurs in the lines and burners whichinterferes with efficient operation. Gradual consumption of the contactliquid shortens the contact time of the air and also results in gradualdrop of the B. t. u. value, which is apt to bring the gas within theexplosive range. Wide variation in the B. t. u. content of the gas alsointerferes with burner adjustment and combustion elliciency.

It is, therefore, the principal object of the present invention toprovide a method of enriching air with a volatile hydrocarbon which is'efficient and safe in operation.

Other objects of the invention are to provide a constant supply ofuniformly enriched gas which is kept above the explosion range of an airvapor mixture and preferably slightly below the full saturation point;to maintain a constant temperature in the zone of enrichment regardlessof variation in atmospheric conditions; to secure a uniformly intimatecontact of the air and contacting liquid over an ample period of timeregardless of the level of liquid carried in the apparatus; to preventcondensation in the lines leading from the generating apparatus to thepoint of use on moderate temperature changes; and to permit the use ofsmaller pipes,

valves and other fittings between the enriching unit and the burners byreason of greater efliciency.

In accomplishing these and other objects of the invention, ashereinafter pointed out, I have provided improved details of structure,the preferred forms of which are illustrated in the accompanyingdrawings, wherein:

Fig. l is a vertical section through a gas generating apparatusconstructed and operated in accordance with the present invention.

Fig. 2 is a horizontal section through the contacting chamber on theline 2-2 of Fig. 1.

Fig. 3 is a cross-section through a portion of the motor blowercompartment on the line 33 of Fig. 1,

Fig. 4 is a detail perspective view of the air contacting passageway.

Fig. 5 is a horizontal section through a portion of. the radial contactpassageway and heater chamber.

Fig. 6 is a vertical section through a modified form of the apparatus.

Fig. 7 is a detail section on the line '!1 of Fig. 6.

Referring more in detail tothe drawings:

I designates a gas generating apparatus in-- cluding a tank or vessel 2having a cylindrical, vertical wall 3, a bottom 4, and a crowned cover5. Extending horizontally across the interior of the vessel, between thebottom 4 and cover 5, are spaced partitions 6 and l, forming a heatingchamber 8 therebetween and respectively cooperating with the bottom 4and cover 5 to form a lower motor and blower compartment 9 and an uppercontact chamber Ill. The contact chamber Ill contains the volatilehydrocarbon, such as gasoline, as indicated at I l, and which isinserted through a filler connection l2 attached to the side of thevessel and normally closed by a plug l3. The level of the liquid in thecontact chamber is shown by a sight gauge l4 that is connected with theside of the vessel and within the normal range of liquid level to becarried in the contacting chamber. 7

Located in the compartment 9 is a blower I5, having its inlet sidelocated in registry with an air inlet opening it that is formed in theside wall 3 and covered by a suitable screen IT. The outlet I8 of theblower is connected by a duct IS with an air inlet connection 20 openinginto the heater chamber 3, which in turn communicates with thecontacting chamber ll! through a centrally located stand pipe 2|. Theblower I5 is operated by a motor 22 that is connected therewith to drivethe blower at a suitable speed for maintaining flow of a predeterminedvolume of air from the atmosphere through the inlet opening l6, and fordischarging the air at higher pressure through the duct l9 into theheating chamber 8 and from the heating chamber through the stand pipe 2|from where it is diverted for travel through the body of contactinliquid l, as now to be described.

Extending radially from the stand pipe 2|, and resting upon thepartition 6, are channel-shaped supports 23 having upper flanges 24sloping downwardly toward the wall 3, as best shown in Fig. 1. Seatedupon the flanges 24, in telescoping relation with the stand pipe 2|. isa contact baffle 25 including a flat, slightly cone-like corrugateddiaphragm 26 having its base periphery terminating short of the wall 3to provide an annular passageway 2'! therebetween, the periphery of thediaphragm having an upwardly directed annular flange or lip 28.Connected with the center of the diaphragm is a cap-like sleeve 29located in covering relation with the stand pipe and having a closedupper end 30, the sleeve being of sufficient length and diameterrelatively to the stand pipe to provide a gas passageway 3| extendingacross the top of the stand pipe, and a vertical, annular passageway 32,encircling the stand pipe, and communicating with the passageway 34through an annular opening 33 in the axis of the diaphragm. The air isthus diverted from the stand pipe 2| and flows downwardly through thepassageway 32 and radially through the passageway 34 in contact with theliquid carried in the contacting chamber. The air, upon contact with theliquid, is enriched by the vapors therefrom and is discharged through anoutlet 35 in the apex of the cover 5.

As above pointed out, the amount of vapor picked up by the air iscontrolled by the temperature and humidity of air drawn into the inletl6, and since apparatus of this character must be constructed to operateat temperatures varying from around 100 F. to a temperature of 35 F., itis impossible at these varying temperatures, to provide a gas having aconstantly uniform B. t. u. content due to variation of absorptioncapacity of the air at different temperatures. For example, with aliquid hydrocarbon having 180 initial boiling point and a 323 end point,which is a distillate cut principally of the parafiin series ofhydrocarbon compounds and falling between C'lHlS and CsHzo, or pentaneand nonane with octane CsHm representing the average composition ofhydrocarbon for use in the apparatus, and with the air supply adjustedso as to fully maintain saturation of the air with distillate vapors ata given temperature, lowering of the temperature results in rapiddecrease in the vapor absorbing power of the air. Actual laboratorytests have shown the following results wherein the 100% column indicatesresults at 100% saturation. In the third column is the vaporizationefficiency which could be obtained in normally good practice.

On vaporizing with, say octane, the upper limit of explosibility is on a210 B. t. u. mixture. By

observing the 80% column it will be noted that in normally good practicethe B. t. u. value is 264, which is above the upper explosive limit. At60 F. and allowing 80% efliciency, the result is noted at 192 which issomewhat under the upper limit of explosibility but not dangerouslyunder it. Below temperatures of 60 F. the resultant gas would be wellwithin the range of combustibility with the result that flash-backs areliable to occur and result in a serious explosion. I therefore providethe chamber 8 with a heater here shown as an electric resistance element36 that is supplied with a suitable current under control of athermostatic regulator 36' so as to maintain a predetermined uniformtemperature of the air discharged into the contact chamber regardless ofthe prevailing atmospheric temperatures. The bulb element 35" of thethermostat may be located at any convenient place in the heat zone ofthe generator or distribution system, but is shown in the drawings aslocated in the manifold connection 39 and operably connected with theswitch element of the regulator controlling electric current to theheating element. The space between the partitions 8 and I is, therefore,insulated circumferentially of the heater, as indicated at 31. and theentire outer side wall 3 and cover 5 are provided with a suitableinsulating cover 38 so as to reduce the influence of externaltemperatures upon the temperature carried within the contacting chamber.By thus maintaining a substantially uniform temperature Within thecontacting chamber, gas having a constant B. t. u. value may bedelivered through the outlet 35 as long as the level of the liquidremains uniformly constant. The gas upon discharge through the outlet 35flows into a manifold connection 39 for distribution to the point of usethrough a pipe line 40. I also find it desirable to cover the pipe linewith an insulating material, indicated at ll, so as to preventcondensation of vapor from the gas incidental to effects of thesurrounding temperature. The inlet of the pipe GE! is provided with asuitable fire-stop in the form of a gauze cone, as indicated at 42, sothat should any flash-back occur in the line it cannot ignite the gasmixture contained in the contact chamber I0. The out let 35 is alsoprovided with a grill 4 3 which serves as a spray eliminator as well asa secondary firestop.

It is apparent that the liquid is gradually consumed so that the levelthereof falls within the contact chamber with the result that the contact period becomes less, and therefore pick-up of the vapor is reducedwith the result that the B. t. u. content of the enriched air dropsbelow that required to maintain the burners operating efficiently. TheB. t. u. content would also drop below that required to keep the gassafely above the combustion range. I therefore provide the apparatuswith means for maintaining a definite contact period of the air with theliquid regardless of the rise and fall of the liquid within the chamberID. This is accomplished by providing a uniformly constant contact headof liquid above the passageway 34.

Supported within the contact chamber H], and having its lower endresting upon the periphery of the diaphragm 26 in inwardly spacedrelation with the flange 28, is an annular wall 44 spaced from the Wall3 to form a vertical passageway 45 through which the enriched air mustpass on its way to the discharge outlet 35. The upper edge of the wall44 forms a weir 56 over which surplus liquid overflows into the body ofthe liquid carried in the contact compartment. Liquid is admitted intothe passageway 45 through a series of perforations 41 that is formed inthe lower edge of the wall 44 in substantially horizontal.

registry with the flange 28. The flange, or 11p 28, directing the airpast the perforations, causes aninducing action whereby liquidis drawn,from the chamber I above the diaphragm and moved upwardly through thepassageway 45 for overflow across .the weir 4'6. Inv order to maintainthe wall 44 in centered relation with the wall 2, the periphery thereofis provided with vertical spacers 41'.

The contact time of the liquid with the air is thus kept, constant as afixed static head is maintained in the passageway 45 incidental to theinducing action of, the air. This constant circulation of the liquidfrom the chamber |D through ration by the air so that the B. t. u.content of the gas is as high as possible to keep it out of theexplosion range and to get greatest efiiciency and capacity from theunit.

In order to maintain the pressure within the contact chamber and pipeline when the blower is out of operation, the discharge end of the standpipe 2| is provided with a gravity valve 48 which is kept open as longas the blower is in operation, but which drops into seating relationwith the end of the pipe when the blower is out of service.

The form of the invention illustrated in Fig. 6 is substantially thesame as that of the preferred form with exception of the arrangement ofcontact passageways. In this form the cap-like sleeve 49, which coversthe stand pipe 50, carries a disk-like baffle that is suspended above ahorizontally arranged secondary baffle 52 which is supported above theupper partition 6 to provide a liquid passageway 53 thereunder. Thebafiles 5| and 52 thus form a radial passageway 54 therebetween throughwhich the air must travel before it can escape over the edge of thebaflie 5|. Extending about the periphery of the bafile 52 is an annularring 55 which projects above the baflle 5| and terminates in an inwardlydirected annular wing 56 for diverting the air toward the axis of thecontacting chamber for return flow across the top of the baffle 5|. Inorder to provide a constant head of liquid through which the air mustmove, the baflies just described are covered by a baffle 51 that isspaced therefrom by an annular flange 58 to provide a liquid passageway59 above the wing 56, and which extends about the periphery of the ring55. The inner periphery of the baffle 51 is connected with a cylindricalcollar 60 that extends upwardly of the sleeve-like cap, in spacedrelation therewith, to form a head of fixed height. In order to supplyliquid to the air passageways, the flange 56 and ring 55 are providedwith ports 6| and 62. The cap-like sleeve 49 carries a deflector plate63 that is spaced above the edge 64 and projects radially to form abafile to prevent any entrained liquid from. being carried with the gasthrough the outlet 35. The stand pipe, cap-like sleeve and cylindricalcollar 60 are spaced apart by suitable spacers 65 and 66, as best shownin. Fig. 7.

The operation of the apparatus constructed and assembled as illustratedin Figs. 1 to 5 inclusive is as follows:

The plug I3 is removed and a suitable liquid hydrocarbon, such asgasoline, is poured into the contacting chamber-through the inletconnection I2 until the level in the contacting chamber sub.- stantiallyreaches the top of the fill connection. The plug I3 is then replacedandthe motor 22 and heater 35 are put in operation by connecting them witha suitable current supply shown in diagram Fig. 1. Air is then drawn bythe blower through the inlet l6 and discharged at higher: pressurethrough the pipe l9 and connection into the heating chamber 8 where theair is brought to the desired temperature as set by the thermostat, forexample the minimum tempera.- ture of 70 F. The heater also raises thetem. perature of the liquid to substantially the air, temperature. Theair discharges from the heating chamber through the stand pipe 2| andlifts the check valve 48 for flow through the passageways SI and 32 inthe sleeve-like cap. The air then moves downwardly through the liquidwhich rises within the sleeve-like cap through the liquid contained inthe passageway 34 where it moves radially in scrubbing relation with thecorrugations on the under side of the diaphragm 26 toward the annularpassageway 21 and over the lip through the liquid carried in the annularpassageway 45. This movement of the air lifts the liquid in thepassageway 45 in the form of bubbles and effects inducing action thereoffrom the contacting chamber through the apertures 41 so that as theliquid is displaced within the passageway 45 it is continuallyreplenished from the main supply. The air is thus thoroughly contactedwith the liquid and is discharged from the top of the passageway intothe space that is carried above the liquid in the contacting chamber.The surplus liquid flowing over the top of the weir 46 falls back intothe body of liquid and the enrichened air discharges through the grill43 into the manifold 39, and through the cone 42 into the pipe 40 whereit flows to the burner.

With the apparatus as above described, the air is kept moving throughthe same hydrostatic head of liquid so that with a uniform temperature,as controlled by the heater, a uniformly enriched mixture is maintainedfor flow to the burner. By proportioning the amount of air andcontrolling the temperature the B. t. u. value may be kept near thesaturation point so that it is well above combustible range, and thereis little or no possibility of flash-back through the pipe line 40 forthe reason that the gas mixture is too rich to produce an explosion.

The form of the invention illustrated in Fig. 6 operates insubstantially the same manner as in the preferred form. In this form ofthe inven tion the air, after being heated, moves downwardly in thepassageway surrounding the stand pipe 50, through the passageway 54 overthe edge of the baffle 5| and inwardly through the passageway 56 forflow up through the passageway formed within the collar 60, the latterpassageway being soproportioned that the air flow induces movement ofliquid through the ports BI and 62 to retain the air passages full ofliquid. The liquid being carried by the air overflows the edge 64 andthe air enriched by the vapors picked up through contact with the liquidis discharged around the periphery of the deflector 65 to accumulate inthe space above the level of liquid in the contacting chamber. Theenriched air or gas is drawn off through the grill 43 in the same manneras described in the first form of the invention.

From the foregoing it is obvious that I have provided a method offorming a combustible gas by enriching air with a hydrocarbon vaporwhich is eflicient in operation and wherein the B. t. u. value of thegas may be kept at a minimum Well above the explosion range.

What I claim and desire to secure by Letters Patent is:

1. The method of preparing and maintaining a normally non-explosive airand vapor mixture including, contacting air and. a volatile petroleumhydrocarbon liquid to eiTect absorption by the air of hydrocarbon vaporsin quantity to form a mixture having a B. t. u. value within a safelynon-explosive range at the upper explosive limit, applying heat in thezone of contact to maintain the absorbing power of the air necessary ineffecting said B. t, u. value upon drop in atmospheric temperature,controlling said heat to maintain a substantially uniform temperaturenecessary to maintain said B. t. u. value of the mixture, and storingsaid mixture and conveying said mixture Without material loss of heat toa point of use.

2. The method of preparing and maintaining a normally non-explosive airand vapor mixture including, confining a body of volatile petroleumhydrocarbon liquid, passing air in sub-surface flow through said liquidin a plurality of superimposed levels to provide contact time for theair to absorb sufficient hydrocarbon vapors to form a mixture having aB. t. u. value within a safely non-explosive range at the upperexplosive limit, applying heat in the zone of contact to maintain theabsorbing power of the air necessary in efiecting said B. t. u. valueupon drop in atmospheric temperature, controlling said heat to maintainuniform temperature of the mixture necessary to retain said B. t. u.value, and storing and conveying said mixture to a point of use Withoutmaterial loss of heat.

ALFRED J. DIESCHER.

